# def f1(a, b):
#     c = a + b
#     return c
#
#
# print(f1(1, 2))

# def f2():
#     print(m)
#
#
# m = 5
# f2()

# def f3():
#     info = '你好'  # 局部变量
#     print(info)
#
#
# info = '不好'
# f3()
# print(info)

# b = [1, 2, 3]
#
#
# def f4(b):
#     b[0] = b[0] + 1
#     return b
#
#
# print(f4(b))
# print(b)

x = 50


def f5():
    global x  # 声明全局变量
    print("x1:", x)
    x = 2
    print("x2:", x)


f5()
print('x3:', x)
